Maximum-demand indicator.



L. T. ROBINSON.

MAXIMUM DEMAND INDICATOR. APPLICATION FILED DEC-31,1913.

Patented Nov. 9, 1915.

Inventor Lewis T. Robinson HIS fittorneg lizzziaM S G S .S m k W unrrnpSTATES PATENT 0mm.

, LEWIS 'r. aoisinson, or SCI-IENECTADY, NEW YORK, AssIGNoR T0 GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

MAXIMUM-DEMAND INDICATOR.

To aZZ whom it may concern Be it known that I, LEWIS 'T. ROBINSON, acitizen of the United States, residing at Schenectady, county ofSchenectady, State of New Yorlnhave invented certain new and usefulImprovements in Maximum-Demand Indicators, of which the following is aspecification.

My invention relates to maximum demand indicating instruments, and inparticular to maximum demand indicators of the type described in myapplication for Letters Patent filed May '22, 1913, Serial No. 769,168.

The maximum demand indicator described in my above identifiedapplication comprises a watt-hour meter element which actuates a movableelement; \Vhen the movable element hasbeen moved a distance which issubstantially a measure of the rate of consumption of energy, it isreturned to its initial or zero position, and the cycle of operations isthen repeated. In the indicator described in my former application anelectromagnet is employed to interrupt the operative engagement of thewatt-hour meter element with the movable element to permit the movableelement to return to its initial position. The circuit of theelectromagnet is completed by a pair of cotiperating contacts, one ofwhich is actuated by the watthour meter element and the other isactuated by an indicating wattmeter element. lVhile I have experiencedno ditficulty in the use of movable electric contacts in this type ofmeter. nevertheless, such contacts are regarded as objectionable andundesirable in commercial types of instruments, and the object of mypresent invention is to eliminate the contacts and the electric circuitincluding the elcctromagnet employed in my former indicator.

The object of my present invention is, accordingly, to .provide meansconsisting entirely of mechanical elements for interrupting theoperative engagement between the watt-hour meter element and the movableelement.

A further object of my invention is to provide the indicating wattmet relement of a maximum demand indicator of the type described in my formerapplication with a. novel device for determining the extent ofSpecification of Letters Patent.

Patented Nov. 9, 1915.

Application filed December 31, 1913. Serial No. 809,825.

movement of the movable element from its initial position as a funct1onof the rate of embodying the novel features of my invention will beunderstood from the following description taken in connection with theaccompanying drawings, in which- Figure 1 is a diagrammatic view inperspective of a maximum-demand indicator embodying the features of mypresent invention; and Figs. 2 and 3 are views illustrating certaindetails of construction.

Referring to Fig 1 of thedrawings, there is shown a system ofdistribution comprising conductors 5 supplying electric energy totranslating devices 6. A watt-hour meter of the induction type isoperatively connected to the system in the usual manner for the purposeof integrating and recording the total quantity of energy consumed inthe translating devices. The induction wattmeter comprises the usualseries coil 7 and potential coils 8 \vhich'produce a rotary magneticfield proportional to the rate ofconsumption of energy in the wellunderstood manner. 7

Two rotatable disk armatures are located within the influence of themagnetic field produced by the coils 7 and 8. One of these diskarmatures 9 is arranged as the rotatable element of a watt-hour meter.Permanent magnets 10 are mounted in operative relation to the diskarmature 9, so that the revolutions of the armature are directlyproportional to the watt-hours of energy consumed in the translatingdevices. The second armature 11 is arranged as the movable elemen of anindicating wattmeter. Permanent magnets 12 are operatively associatedwith the indicating wattmeter armature 11.

A shaft 13 is rigidly secured to the indicating wattmeter armature 11. Acontrol spring 17 is operatively connected at one end to the shaft 13and at the other end to a fixed part 18 of the instrument. The controlspring is designed to render the movement'ot the disk mnature 11 ameasure of the strength of the magnetic field, and thus ameasure of therate of consumption of energy. The disk armature 11 moves in a is soproportioned and positioned that when v the indicating wattmeterarmature is in its initial or zero position the arm 38, hereinafter moreparticularly referred to, is a minimum distance from the periphery ofthe cam 20, and when the armature has moved to its limiting position ina clockwise direction the arm 38 is a maximum distance from theperiphery of the cam. The

stop thus prevents inaccurate registrations in cases where the rate ofconsumption of energy is so excessive as to turn the indicatingwattmeter armature through an angle greater than 360, and also preventsdamage t the arm 38 which would be likely to occur if the movement ofthe cam 20 were not restrained within certain limits.

A shaft 21 is rigidly secured to the rotatable disk 9 of the watt-hourmeter element.

The shaft 21 drives, through gearing 22, the usual registering mechanismofthe meter. The registering mechanism has been omitted in the drawingsas it forms no part of my invention. The rotatable shaft 21 also drives,through the worm gearing 23, a ver tically arranged shaft 24. A pinion25 is mounted on the shaft 2% and is adapted to be driven thereby bymeans of a resilient connection shown in detail in Figs. 2 and 3. Thepinion 25 is primarily loosely mounted on the shaft 24. A hub 26 isrigidly secured to the shaft 24 and is provided with a pin 27 whichextends through a slot 28 in the pinion A leaf spring member 2 issecured at one end to a pin carried by the pinion 25 and at the otherend to the pin 27, and normally tends to hold the pin 27 in one end ofthe slot 28. It will thus. be seen that a certain relative movement ofthe pinion 25 with respect to the shaft 24 is permitted bv thisresilient connection.

A longitudinally n'u'ivable member 30 is supported upon a horizontalbase plate 31 and is provided with a rack 32 adapted to mesh with thepinion 25. A rod 33 is pivoted in blocks 34 and 35? mounted on themovable member 30-. A catch 36 is rigidly secured to the rod 33, and isprovided with a notched portion adapted to e'\gage with a guide member37. When the notched poriege-o0 tion of the catch 36 operativelyengageswith the edge of the guide member 37 the rack 32 is held in operativeengagement with the pinion 25. A fixed block' 51 cooperates with thepinion 25 and the catch 36 to aline the path of movement of'the member30.

A movable arm 38 is pivoted to the block 35. A finger 39 is secured tothe arm 38 and rests upon a finger 40 secured to the rod 33. A leafspring 41 is secured to the movable member 30 by means of an 'arm 42 andextends under the fingers 4:0 and 39. The. action of the spring 4:1 isthus to force the finger 4O upwardly thereby insuring the engagement ofthe catch 36 with the guide member 37.

A cam 20 is rigidly secured to the shaft 13 of the indicating wattmeterelement. This cam is so shaped that the distance from the initialposition of the movable member 30, and, accordingly, the distance fromthe initial position of the arm 38, in the path of movement 9f thesemembers, to the periph cry of the cam'is substantially a measure of therate of consumption of energy'in tli'e' translating devices 6. D

The remaining details of construction of my improved maximum demandindicator will be best understoodfrom a description of the operationthereof.

The initial position of the movable mem ber 30 is determined when thismember rests against a fixed stop 43. As energy is consumed in thetranslating devices 6 the indicating wattmeter armature 11 will take up,

riphe'ry of the 3am 20. lVhen the movable member 30, and, accordingly,the movable arm 38. have moved a distance from their respective initialpositions which is substantially a measure of the rate of consumption ofenergy in the translating devices 6, the periphery of the cam 20 willintercept the movement of the arm 38. As the movable member 30 continuesto advance the arm 38 is slightly turned, thus forcing its finger 39downwardly against the action of the spring 4-1. This downward motionof. the finger 39 turns'the rod 33 and raises the catch 36 fromoperative engagement with the guide 37. A spring 44, secured at one endto the arm 42 and at the ther end to a fixed part of the supportingplate 31, now pulls the rack 32 out of engagement with the pinion 25'andalso pulls the movable movable member 30 reaches its initial position awheel 45, secured at one corner of' sufiiciently far removed from theguide member 37 for the notched portion of the catch 36 to drop intooperative engagement with the guide member. The cycle-ofoperations isthen repeated.

If the consumption of energyin the trans lating devices 6 is interruptedbefore the arm 38 is intercepted by the periphery of the cam 20, the camwill rotate in a counterclockwise direction due to the return of thewattmeter disk 11 to its initial position, and

in this counter-clockwise rotation the pe riphery ofthe cam will strikethe arm 38, and the movable member 30-will be returned to its initialposition. The movable member 30 is thus returned to its initial positioneach time that the consumption of energy in the installation isinterrupted and a new measurement of demand isaccordingly begun eachtime that the consumption of energy is resumed.

The maximum movement of the movable member 30 is indicated by anon-return pointer L? which sweeps across a coiiperating scale 48. Thepointer is pivotally mounted in a block 49 secured to the supportingplate 31, and its pivoted sleeve is provided with a lug 50 which lies inthe path of movement of the upper end of the rod 33. The rod 33 thusengages with the lug 50 and moves the pointer 47, thereby indicating themaximum movement of the movable member from its initial position.

Numerous modifications in the details of construction of my improvedmaximum demand indicator will be evident to those skilled in the art.\Vhile I have described my invention, for the purposes of illustration,embodied in an instrument of the induction meter type having all or itsoperative elements actuated by the same field coils, it will be obvipusthat my invention is not limited either to an instrument of thisparticular type or to an instrument in which the watt-hour meter elementand the wattineter element are actuated by the same field coils. I donot, therefore. desire to be limited to the specific construction whichl have herein described and illustrated, and I aim by the terms of theappended claims to cover all modifications which are within the spiritand scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,

1. A maximum demand indicator comprising in combination an electricmotor meter element, an indicating electric meter ele ment adapted toalways occupy a position which is substantially a measure of the rate ofconsumption of energy, a movable member adapted to be actuated by saidmotor meter element, means consisting entirely of mechanical elementsoperatively related to said movable member and cooperating with saidindicating meter element' for interrupting the movement oi said movablemember when the distance the member has moved from its initial positionmeans consisting entirely of mechanical elements and including said lastmentioned means operatively related to said movable member andcooperating with said indicating wattmeter element for interrupting theoperative connection between said watt-hourmeter el ment and saidmovable member when "vie distance the member has moved fr om its initialposition is substantially a measure of the rate of consumption ofenergy, and means for indicating the maximum movement of said movablemember.

3. A maximum demand indicator comprising in combination a watt-hourmeter element, an indicating wattmeter element adapted to always occupya position which is substantially a measure of the rate of consumptionof energy, a movable member adapted to be actuated by said watt-hourmeter element, means consisting entirely of mechanical elementsoperatively related to said movable member and cooperating with saidindicating wattmeter element for interrupt-ing the movement of saidmovable member when the distance the member has moved from its initialposit-ion is substantially a measure of the rate of consumption ofenergy, and means for indicating the maxi.-

mum movement of said movable member.

4. A maximum demand indicator comprising in combination a watt-hourmeter element, an indicating wattmeter element having an initialposition and adapted to always occupy a position whose distance fromsaid initial position is substantially a measure of the rate ofconsumption of en ergy, a movable member having an initial position'andadapted to be actuated by said watt-hour meter element, means consistingentirely of mechanical elements operatively related to said movablemember and coop- ,eratin with said indicating wattmeter element orreturning said movable member to its initial position when the distancesaid n1ember has moved from its initial position isa predeterminedfunction of the distance of said indicating'wattmeter element from itsinitial position, an'dmeans for indicating the maximum movement of saidmovable 5. A maximum demand indicator comprising in combination awatt-hour meter elementand an indicating wattmeter element, a movablemember having an initial.

position, means for operatively' connecting said watt-hour meter elementto said movable member, a second movable member operatively connected tosaid indicating wattmeter element, and means consisting entirely ofmechanical elements and opera- I tively related to said first mentionedmovable member adapted to engage with said second movable memberswhereby said fimtmentioned moy able member isereturned to its initialposition; and means for indicating the maximum movement of said firstmentioned movable member.

6. A maximum demand indicator comprising in combination a watt-hourmeter element and an indicating wattmeter element, a movable memberhaving an initial position, means for operatively connecting saidWatt-hour meter element to said movable member, an involute-slnlped camoperatively connected to said indicating wattmeter element, an armcarried by said movable member and having a path of movement whichalways intersects the periphery of said cam, means operatively relatedto said arm whereby said movable member is returned to its initialposition when the periphery of the cam intercepts the movement of saidarm, and means for indicating the maximum movement of said movablemember.

7. A maximum demand indicator comprising in combination a watt-hourmeter element and an indicating \vattmeter ele 'ment, anll1\'0lllt;l1:l176(l cam operatively connected to said indicatingwattmeter element,'a movable element having an initial position andadapted to be actuated by said watt-hour meter element and having a pathof movement which always intersects the peri'phery'of said cam, meansoperatively related to said movable element whereby said element isreturned to itsinitial position when the periphery of said camintercepts the movement of the movableelem'ent, and

means for indicating the maximummove ment of sald movable elementr 8. Amaximum demand indicator comprising in combination a watt-hour meterelement and an indicating wattmeter element, a movable element having aninitial position and adapted to be actu'ated by said Watt-hour meterelement, a cam operatively connected to said indicating wattmeterelement and so shaped that the distance from p the initial position ofsaidmovable element to the periphery of said cam is substantially ameasure of the rate of consumption of en} ergy, said movable elementbeing so arranged that its path of movement always intersects theperiphery of said cam, means operatively related to said {movableelementv whereby said element is returned to it's ini tial position whenthe periphery of said cam intercepts themovement of the movable element,and means for indicating the maximum movement of said movable element.

9. A maximum demand indicator comprising in combination a watt-hourmeter element and an indicating wattmeter 'e'fe ment, a movable memberhaving an initial position, means whereby said movable member isoperatively connected to said Watthour meter element, a cam operativelyconnected to said indicating wattmeter element and so shaped that thedistance from the initial position of said movable member to theperiphery of said cam is substantially a measure of the rate ofconsumption of energy, an arm carried by said movable member and havinga path of movement which always intersects'the periphery of said cam,

means for normally maintaining said movable member operatively connectedto said watt-hour meter element, means actuated by said arm when theperiphery of the cam intercepts the movement of the arm for plac-

